1. Field of the Invention
The invention relates to an externally supplied arrangement having an electronic display and/or a communication interface.
In a preferred embodiment of the invention, the arrangement is any measuring, tariff or recording apparatus but preferably a gas, water or power consumption measuring apparatus such as for example an electronic electricity meter. The arrangement has an electronic display which displays measured, calculated and/or other variable parameter values stored in the memory. In the case of electricity meters the measured parameter values are for example energy, power, voltage or current values while for example there is a customer number as another variable parameter value, that number differing from one electricity meter to another. The parameter values are stored in a memory in the arrangement and, in addition to the display or also in place of the display, can also be transmitted to the exterior, for example for remote reading, by way of a communication interface.
2. Description of the Prior Art
In operation of a known such arrangement energy is generally supplied to the arrangement from an electrical power supply mains. In certain cases, for example in the event of a mains failure, on building sites, in a situation involving seasonal operation, in locomotives with retracted current collector or during storage, the electrical power supply mains is not yet connected or is not yet switched-on so that the electronic display and the communication interface are relatively worthless as electrical energy is required to permit them to be read or for operation thereof. In all those cases the stored parameter values can therefore be read only when the arrangement is supplied with energy from the electrical power supply network. That is in contrast to arrangements equipped with a mechanical counting mechanism in which the displayed parameter value is readily readable in all the above-indicated situations (mains failure, building site, seasonal operation, locomotive, storage) because, as is known, no electrical power supply is required for a mechanical display and for reading thereof.
The use of batteries is unusual in such arrangements which are generally operated over a long-term period of operation, for example for a period of ten years, and - by virtue of possible discharging of the batteries--involves difficulties in the course of time. For the same reason it is not very sensible for the arrangement already to be fitted with a battery during storage.
It is conventional that such arrangements, especially when used as consumption meters are sealed. As is known security seals protect electricity meters from unauthorised manipulation. In that situation a lead-sealed cover prevents the electricity meter from being accessible for a direct supply from the exterior, without destruction of the security seal.
An electronic electricity meter provided with a solar cell is known from US-A-5 197 291, in which the electronic system is supplied by a battery which, to ensure battery power when the arrangement is subjected to the effect of solar radiation, is cooled by a cooling assembly which is powered by a solar cell.